staging: usbip: remove redundant return statements

Remove redundant return statements at the end of void functions. This
addresses the checkpatch.pl warnings:

	WARNING: void function return statements are not generally useful

Signed-off-by: Max Vozeler <max@hinterhof.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --cc drivers/staging/usbip/stub_rx.c
Simple merge

diff --cc drivers/staging/usbip/vhci_hcd.c
Simple merge

diff --cc drivers/staging/usbip/vhci_rx.c
Simple merge